Simplified chassis for electronic equipment



Jan. 8, 1952 D. H. MITCHELL SIMPLIFIED CHASSIS FOR ELECTRONIC EQUIPMENT8 Sheets-Sheet 1 Filed April 11, 1947 INVENTOR. jozzazi/f/f zzafiei gvwmM 8 Sheets-Sheet 2 D. H. MITCHELL SIMPLIFIED CHASSIS FOR ELECTRONICEQUIPMENT Jan 8, 1952 Filed April 11, 1947 W fm QNN Jan. 8, 1952 D. H.MITCHELL SIMPL "IED CHASSIS FOR ELECTRONIC EQUIPMENT 8 Sheets-Sheet 3WNN @NNN

MNN

Jam 1952 D. H. MITCHELL 2, 67

SIMPLIFIED CHASSIS FOR ELECTRONIC EQUIPMENT Filed April 11, 194? 8Sheets-Sheet 4 OZ MW fm Jan. 8, 1952 D. H. MITCHELL SIMPL IED CHASSISFOR ELECTRONIC EQUIPMENT 8 Sheets-Sheet 5 Filed April 11, 1947 BY Z Jan.8, 1952 D. H. MITCHELL 2,581,967

SIMPLIFIED CHASSIS FOR ELECTRONIC EQUIPMENT Filed April 11, 1947 sSheets-Sheet e [III/IIII/IIIL JNVENTIOIR.

D. H. MlTCH ELL 2, 8 67 SIMPLIFIED CHASSIS FOR ELECTRONIC EQUIPMENT -8Sheets-Sheet 7 Jan. 8, 1952 Filed April 11, 1947 Jan. 8, 1952 D. H.MITCHELL 2, 7

SIMPLIFIED CHASSIS FOR ELECTRONIC EQUIPMENT Filed April 11, 1947 8Sheets-Sheet 8 Patented. 'Jan. 8, 1952 SIMPLIFIED CHASSIS FOR ELECTRONICEQUIPMENT Donald H. Mitchell, Chicago, Ill., assignor to Motorola, Inc.,a corporation of Illinois Application April 11, 1947, Serial No. 740,825

to a radio receiver including a simplified chassis on which thecomponents of the receiver are mounted.

In the prior art it has been the general practice to provide a chassisfor a radio transmitter or receiver on which the various components ofthe transmitter or receiver are mounted. The chassis is then mounted ina cabinet which encloses the transmitter or receiver, the chassisincluding the operating parts of the set being generally independent ofthe cabinet. The components are then connected in a circuit byconnecting wires thereto, this generally being accomplished by solderingthe wires to terminals provided on the components. The mounting andconnecting of the components is for the most part done by hand andrequires a relatively large amount of time. Various attempts have beenmade to provide a chassis wherein the conductors necessary forconnecting the components of the set in a circuit are built directlyinto the chassis, but difllculty has been encountered in such chassis inproviding a simple arrangement for the conductors to cross each other asis required in the usual circuit for radio or other electronicequipment. This and other difilculties have resulted in such chassisbeing complicated and expensive to manufacture thereby generally defeat.ing the purpose of the composite chassis, that is to reduce the timerequired in assembling and wiring the set and thereby substantiallyreduce the manufacturing cost thereof.

It is an object of the invention, therefore, to provide an improved andinexpensive chassis for electronic equipment in which means'forinterconnecting the components is provided as a part of the chassis. v

It is a further object of this invention to provide electronic equipmentincluding a chassis with a plurality of circuit components thereon, inwhich the chassis includes connecting means having quick detachableterminals for supporting and electrically connecting the components.

A still further object of this invention is to provide improved plug-interminals for mounting and connecting various electronic circuitcomponents.

It is another object of this invention to provide I an improved radioreceiver in which all the operating components are mounted on a chassiswhich is supported in a cabinet in an easily removable manner.

A feature of this invention is the provision of a chassis for electronicequipment made of two sheets of insulating material with a plurality ofprefabricated conducting strips supporting therebetween which includeterminals arranged to support and electrically connect the components ofthe equipment.

A further feature of this invention is the provision of a radio chassisincluding conducting strips supported between insulating sheets forconnecting components of the equipment in a circuit, in which certain ofthe components are utilized for providing the necessary crossovers ofthe conducting strips.

Another feature of this invention is the provision of conducting stripshaving terminals thereon including resilient portions adapted toremovably support and electrically connect electrical components.

A still further feature of this invention is the provision of a radioreceiver chassis on which the components of the receiver are supportedand which includes a. frame work on which a loop antenna is wound, thechassis including connecting means permitting easy removal of thechassis and all operating structure of the receiver from the receivercabinet.

Further objects, features and advantages of this invention will beapparent from a consideration of the following description taken inconnection with the accompanying drawings in which:

Fig. 1 is a perspective view of a radio receiver in accordance with theinvention;

Fig. 2 is a cross-sectional view along the lines 2-2 of Fig. 1;

Fig. 3 is a view of the radio receiver chassis from the tube side;

Fig. 4 is a view of the chassis from the pin" side;

Fig. 5 illustrates the framework for supporting the loop antenna fromthe chassis;

Fig. 6 is a detailed View showing the manner in which the framework ofFig. 5 is connected to the chassis;

Figs. 7 and 8 illustrate a modified structure for supporting the loopantenna from the radio chassis;

Fig. 9 is an interior view of the receiver cabinet illustrating themanner in which the chassis is mounted thereon;

Figs. 10 and 11 are detailed views of the chassis supporting clips;

Fig. 12 is a detailed view of the modified chassis supporting clip;

Fig. 13 illustrates the manner in which an electrolytic condenser issupported on the chassis;

Figs. 14 and 15 illustrate a resistor mounting;

Fig. 16 illustrates the mounting of the volume control on the chassis;

Fig. 1'! is a, detail or the volume control mounting bracket;

Figs. 18 and 19 illustrate the means for connecting a round terminalsuch as a vacuum tube mounting of a ing conducting strips;

Figs. 33 and 3% illustrate a mounting for a rectanguiar resistor;

lug. 35 illustrates a combined condenser and resistor mounting and acircuit crossover;

Fig. 36 illustrates an alternative method of providing crossover of theconducting strips;

Fig. 37 is a view from the pin side of a very small chassis inaccordance with the invention; and

rigs. 38 and 39 are cross-sectional views showing the mounting ofvarious components on the chassis of Fig. 37.

In practicing my invention I provide a chassis for supporting andinterconnecting the components of electronic equipment consisting of apair of insulated sheets each of which have openings therein and aplurality of conducting strips positioned between the sheets havingterminals thereon for supporting and connecting the components of theelectronic equipment. The components are arranged with vacuum tubes,intermediate irequency units, and other large components supported onone side of the chassis and with condensers and resistors and similarcomponents supported on the other side of the chassis. The terminals ofthe vacuum tubes and intermediate frequency units extend throughopenings in the sheets and make connection with the terminals of theconducting strips. Connections are made to the resistors and condensersthrough terminals on the strips which project through openings in one ofthe insulating sheets and form clips for removably supporting andconnecting the components. The conducting strips are constructed withthe terminals arranged to be positioned in openings in one of theinsulating sheets to properly position the conducting strips. The spacewithin the insulating sheets and between the terminals for supportingcomponents such as resistors and condensers may be utilized forconducting strips in other circuits to thereby provide simple circuitcrossovers. Alternatively a conducting strip may have a portion thereofformed as a loop which extends through an opening in one of the sheetsto permit crossing over another conducting strip. The chassis alsoincludes quickly detachable connectors for mounting the chassis in theradio cabinet and a framework for supporting a loop antenna. Thisprovides a complete operable radio receiver illustrate a grounding clipfor which may be easily removed from the cabinet.

Referring now to the drawings, Fig. 1 illustrates a radio receivergenerally indicated at I00 and including a tuner control wheel IN. ascale I02 and pointer 503 for indicating the setting of the tuner, anda. volume control wheel H34. A grille work. 505 is provided above thescale adjacent to which a loud speaker is'placed as will be described.It is to be pointed out that the particular cabinet design and thearrangement of the components therein is merely illustrative and variousother designs and arrangements are possible in accordance with theinvention.

The position of the radio chassis in the receiver cabinet is illustratedin Fig. 2, which shows the chassis H0 vertically positioned with loudspeaker III adjacent the grille I05 and with the pointer I03 extendingthrough opening I06 in the cabinet. The chassis H0 is composed of a pairof insulating sheets H2 and H3 between which a plurality of metalconducting strips H4 are supported. A plurality of openings are providedin the sheets through which terminals of the conducting strips H4 andterminals of the equipment supported on the chassis extend. It isapparent from Fig. 2 that the tubes H5 and intermediate frequency unitsII! are supported on one side of the chassis which will be referred toas the tube" side of the chassis and that resistors H8 and condensers H9are mounted on the other side of the chassis which will be generallycalled the pin side of the chassis. A dial light I2Ia is provided on thepin" side of the chassis and arranged so that light therefrom projectsthrough a slot I01 in the cabinet for the receiver to illuminate thescale I02. The chassis includes a central opening through which themagnet structure of the loud speaker III is positioned, the speakerbeing supported by bracket H6. An output transformer I2I is alsosupported by the loud speaker supporting bracket IIB.

Fig. 3 is a view of the chassis from the tube" side showing thearrangement of the tubes H5, intermediate frequency units H'l andelectrolytic condenser I25 on the chassis. This figure also illustratesthe position of the loud speaker III, the tuner I26, and the volumecontrol I21 which are positioned on the pin side of the chassis. Aconducting coating I20 is provided on the insulating sheet H2 on thetube side of the chassis. This coating can be provided by securing ametal foil on the sheet H2 or depositing a conducting coating thereon.The coating may be grounded so that the shielding cans of the variouscomponents can be automatically grounded by making contact therewith.Other circuits can be grounded to the coating as will be hereinafterdescribed.

The construction of the scale pointer I03 and the manner in which it issupported on the chassis and is moved in accordance with the position ofcontrol wheel IN is apparent from Figs. 2, 3 and 4. The pointer isformed of wire and includes two arms I22 having curved ends I23 adaptedto hook over the bottom edge of the chassis as shown in Fig. 2. Thechassis includes a slot at the bottom along which the pointer may slide.A tip I24 (Fig. 2) of plastic or other material which will make apleasing appearance may be provided for the end of the pointer extendingthrough slot I06. The pointer I03 is supported and moved by a flexiblecable I28 which is wound about the shaft on which the control wheel IIIIis mounted so that movement of the wheel will be transmitted to thepointer. Openings I29 are provided in the chassis to support and guidethe cable.

Fig. 4 is a, view from the pin side of the chassis with a part of theinsulating sheet II3 broken away to better show the position of theconducting strips H4. The complete interconnecting wiring for thevarious components on the receiver is shown in this figure. Theconducting strips II4 are illustrated as being of various shapes, thestrips generally having terminals on the ends thereof and many stripshaving branches thereon so that a plurality of terminals may be providedon the strip. The strips may be punched from any suitable conductingmaterial such as brass which is sufliciently rigid to support thecomponents and resilient so that the components can be snapped in placeand held there. As will be explained more in detail the terminals extendthrough openings in the sheet II: to properly position the strips on thechassis, the strips being held in place when the sheets I I2 and I I3are secured together. It is not believed necessary to point out indetail the connection of all the various components shown in Fig. 4, butcertain components which are representative of the complete chassis willbe described and the detailed mountings therefor will be explained inconnection with the figures showing such mountings.

For providing crossover of the conducting strips, openings are providedin the sheet H3 into which a loop formed in one of the strips may extendto provide clearance between the strips. This feature is illustrated inFigs. 20 and 21 in which a strip I30 is illustrated having a loop I3Iformed therein which is adapted to be positioned in opening I32 in theinsulating sheet I I 3. After the loop I3I is positioned in the openingI32 a second strip I33 can be placed on the insulating sheet II3 withthe space between the strips I30 and I33 preventing shorting of the twocircuits. The loops in the conducting strips together with the terminalsthereon may be used to accurately position the strips with respect tothe sheet to facilitate assembly thereof. A plurality of crossovers asabove described appear in Fig. 4, the crossovers indicated at I36, I31and I38 being examples. Fig. 36 illustrates a modified crossoverarrangement wherein an opening I34 is provided in the sheet II3 having atongue I35 extending therein. It is apparent that the strip I30 may bepositioned on the sheet H3 and the loop I3I in the strip slid under thetongue I35. The tongue I35 provides insulating material between thestrips I30 and I33 to positively prevent interconnection thereof.

In Fig. 4, the tuner I26 is shown supported on the chassis by twomounting screws I40 and HI. The tuner may be of any desiredconstruction, a tuner as disclosed in my copending application, SerialNo. 728,695, filed February 14, 1947, being especially suitable. It isnoted that the mounting screws I40 and HI make connection withconducting strips I45 and I46 respectively, the tuner frame beingutilized to continue the grounding connection between these two strips.For connecting the tuner in the radio circuit, pins I42, I43 and I44 areprovided thereon which are preferably round and make connection withconducting strips I41, I40 and I49 in the manner shown in Figs. 18 and19. In these figures a round pin I50 is shown positioned in a, U-shapedresilient terminal II. The terminal I5I is provided on the end of aconducting strip H4 and is positioned in an opening I52 in the sheet H3.As is clearly shown in Fig. 19 the terminal I5I is split to provide fourclamping edges which engage the pln I50 to firmly secure the pin in thesocket and make good electrical contact therewith. A struck out portionI53 anchors the terminal securely to the insulating sheet I I3.

The conducting strips I41, I48 and I49 connect the tuner I26 toconverter tube I55, the tube including .pins I56, I51 and I58 engagingthe terminals on the conducting strips I41, I48 and I49 respectively andother pins engaging other strips for properly connecting the tube in thecircuit. The pins of the vacuum tube I55 may be the usual round pinswhich may be connected to the conducting strips in the mannerillustrated in Figs. 18 and 19, and previously described. Alternatively,terminals as illustrated in Figs. 2'1 and 28 may be used for connectingthe tube. In these figures, the strip II4 terminates in a cup-shaped endI60 which is split to form a clamping surface which will make a tightconnection with the tube pins. A clip portion I6I may be punched out ofthe strip H4 and snapped into an opening I62 in the insulating sheet II3to anchor the terminal in place, an opening I63 is of course provided inthe insulating sheet II2 through which the tube pin may extend.

For connecting resistors H8 in the circuit, projections are provided onthe conducting strips II4 which extend through openings in the sheetII3. Such projections are shown on conducting strips I48 and I49 (Fig.4) with the projections being indicated as I65 and I66. The constructionof the resistor terminals will, of course, depend upon the type ofresistor used. Figs. 14 and 15 illustrate terminals adapted to supportand connect a resistor in the form of a small cylindrical rod ofcompressed resistance material. In these figures, the conducting stripsIl4 include resilient U-shaped projections I10 on the ends thereof whichextend through openings I1I in the insulating sheet H3. The projectionsI10 include a surface I12 which is roughened as by knurling or gratingagainst which an end of the resistor is positioned, and projecting edgesI13 to prevent displacement of the resistor due to movement from theside. A struck out portion I14 is provided on the U-shaped projection toanchor the terminal to the insulating sheet II3. Fig. 31 illustrates asomewhat simpler mounting for a cylindrical rod type resistor comprisingprojecting terminals I61 having cupshaped ends into which the resistoris seated. The terminals are resilient to hold the resistor in place andinclude projections I68 at the center thereof for making good electricalcontact with the resistor.

In Figs. 33 and 34 terminals I15 are illustrated which are adapted toreceive a fiat resistor I16. Such a resistor might be formed ofcompressed resistance material having conducting material I11 on twoedges thereof. The terminals I15 project through an opening I18 in theinsulating sheet H3 and the resistor is slid down between the terminalsagainst the insulating sheet II2 to provide a secure mounting therefor.

In Fig. 4 there is illustrated a plurality of paper type condensers,some of these condensers being designated I80, I84, I and I86. Thesecondensers are formed by rolling a pair of conducting sheets withdielectric material interposed therebetween and having one conductingsheet extend to one end of the roll and the other I strips NH and sheetextend to the other end so that connection can be made to the two sheetsby making contact with the ends of the roll. The condenser I80 issupported and connected by conducting I82. The conducting strip l8l isof the type previously described whereas the conducting strip I82 is astrip extending across the top of the chassis being connected to one ofthe mounting studs I83 for the loud speaker bracket H6. Other condenserssuch as I84, I85

and I86 are supported on each end by the usual conducting strip-s. Figs.25 and 26 illustrate the details of the mounting for such condensers,the mounting including resilient U-shaped terminals I90 on the ends ofconducting strips ll i which extend through openings l9! in theinsulating sheet H3. Each of these terminals includes a roughenedsurface l92 which is arranged to apply pressure to the end of acondenser as is illustrated in Fig. 25; A struck out portion E93 engagesthe insulating sheet M3 to hold the terminal in place.

Condensers in the form of thin round wafers are also used in the circuitand are indicated at I95 and H36 in Fig. 4. These condensers are adaptedto be connected in a circuit by making contact to the faces thereof. Thedetails of the mounting for this type of condenser are illustrated inFig. 24 which illustrates the wafer as mounted in the opening E9? in theinsulating sheet H3 with one of the conducting strips ll i havingextension i98 overlying a second conducting strip and the condenser I99positioned therebetween. The second conducting strip and the extensionhave projections 29d thereon which make electrical contact with the twofaces of the condenser.

The mounting of the electrolytic condenser His is illustrated in Fig. 13which shows the condenser including a can 20! having projections 202which extend through openings in the chassis, the projections 202 beingtwisted to hold securely the can in place. Any other suitable means can,of course, be used for securing the condenser on the chassis. Fiatconnecting pins 203 are provided for making connection to the conductingstrips, the specific terminal used for making connection to the pinsbeing illustrated in Fig. 23. As previously stated the electrolyticcondenser is mounted on the tube" side of the chassis and the pins 203extend through openings in the chassis and connections are made theretoon the pin" side of the chassis. In Fig. 23, a terminal 295 isillustrated on the end of the conducting strip li the terminal being ofU-shaped configuration and having punched out portions 206 and 207 oneither side of the U adapted to engage the fiat side of a pin 208 whichis positioned therebetween. The terminal is made of resilient materialso that it will adjust itself and make good connection to the pin evenwhen slight errors in positioning occur due to manufacturing tolerances.The terminal includes a struck out portion 289 lor anchoring the same tothe insulating sheet H3.

The mountings of the intermediate frequency coil units ill are generallysimilar to that of the electrolytic condenser except that the shield canis not integrally connected to the coil unit. Fig. 22 shows the mountingof the intermediate frequency coil unit which includes fiat connectingpins 2H0 which extend through the chassis and engage terminals asillustrated in Fig. 23 and previously described.

The can 2H for the unit includes a plurality of lugs 2I2 which arepositioned through openings in the chassis and then twisted to-hold thecan securely to the chassis. As in the case of the electrolyticcondenser, the can is grounded to the conducting coating I20 on thesheet H2. As previously stated, however, the coil unit H1 may be securedby the terminals m alone and the can separately supported on thechassis.

The method of mounting and connecting the volume control i2? isillustrated in Figs. 16 and 17. The volume control is illustrated asincluding three terminals M5, 2th and 2 which are preferably flatconnecting pins similar to those on the electrolytic condenser andintermediate frequency unit and which will be arranged to engage similarterminals (illustrated in Fig. 23).

These connecting pins are positioned on the body portion of the volumecontrol indicated as 8, as is clearly shown in Fig. 4. For supportingthe other end of the volume control on which the operating wheel 1M ispositioned, a supporting bracket M9 is provided. This bracket includesan opening 220 through which the control shaft extends and a projectinglug 22! which is positioned in an opening of the chassis and thentwisted to secure the supporting bracket 2W firmly to the chassis (Fig.17). As is apparent from a consideration of Figs. 1 and 4 the controlwheel I04 of the volume control and also the control wheel ill! of thetuner are positioned so that they may extend through openings in achassis to be in operating position at the front of the cabinet.

In Figs. 29 and 30 there is illustrated a clip 222 which is used in thechassis for grounding a pin, such as a vacuum tube terminal, to theconducting coating on the tube side of the chassis. Such a clip isillustrated for grounding the pin 223 of the vacuum tube in the lowerlefthand corner of Fig. 4. The clip 222 includes a body portion whichextends between the insulating sheets 1 l2 and i1 i3 having an openingadapted to securely engage a pin. The clip also includes a hook portion226! which extends through sheet H2 and securely engages the conductingcoating M0 thereon to provide a grounding connection for the pin 223.

For connecting an antenna to the radio circuit formed by the conductingstrips in the chassis, terminals 225 and 225 are provided (Fig. 4).These terminals are adapted to receive round pins which can be providedon the ends of the antenna wire. The antenna is supported by a frameworksecured to the chassis as will be here inafter explained. For connectingthe loud speaker to the radio circuit, terminals 227, 228 and 229 areprovided. These terminals are adapted to receive round pins and arearranged close together in a row so that a standard plug can be used toconnect the leads from the loud speaker into the circuit.

In applying the chassis in accordance with the invention to complicatedelectronic equipment, many applications will be encountered in which aconducting strip is required for making a common connection to a greatnumber of components. Such strips may be very long and include a greatnumber of terminals making it impractical to punch out the strip withsuflicient accuracy that the terminals of the strip will fit properly inopenings provided therefor in the insulating sheets of the chassis. Insuch instances it may be desirable to divide the strip into a pluralityof shorter strip parts which may be connected to each other in themanner illustrated in Fig. 32. In this figure the conducting strip 23!!includes a resilient U-shaped terminal 23! thereon generally similar tothe terminal 11- lustrated in Fig. 23 for connecting flat connectingpins. This terminal includes punched out portions 232 on the two sidesof the U-shaped terminal and a slotted end portion 233. The conductingstrip 234 includes a right angle projection 235 adapted to be positionedin the U- shaped portion 23! whereby it is engaged by the punched outportions 232, the strip 234 having a reduced portion 236 adapted to fitin the slot 233 of the terminal. It is, therefore, seen that a simpleand effective arrangement for electrically connecting the conductingstrips 233 and 234 is provided.

It may be desirable in certain applications to provide a combinedmounting for a condenser and a resistor. That is, in applications wherea condenser is used to bypass a resistor, a combined mounting for thecondenser and resistor can be provided. Such an arran ement asillustrated in Fig. 35 wherein a con nser mounting as illustrated inFigs. 25 and 26 is combined with a resistor mounting as illustrated inFigs. 15 and 15. The condenser mounting comprises a resilient U-shapedterminal 240 which is connected by a strip 24! to a U-shaped resistorterminal 242. Although similar terminals are shown connecting the otherends of the condenser and resistor, it is obvious that the condenser andresistor might have only one common terminal with separate terminals forthe other ends of the components.

Fig. 35 also illustrates the use of a resistor and a condenser to form acircuit crossover. That is, the condenser and resistor provide acrossover of a circuit in which they are connected with the circuit ofconducting strip 243 positioned in the chassis directly below thecomponents. It is obvious that this arrangement can be used for a singlecondenser or resistor individually, Fig. 25 illustrating a conductingstrip 244 which extends under a condenser and Fig. 14 illustrating aconducting strip 245 extending under the resistor of this figure.

The manner in which the loop antenna and the back closure of thereceiver is supported on the receiver chassis is illustrated in Figs.and 6. In Fig. 5, a framework of fiber or other insulating material isshown supported to the corners of the chassis, the framework comprisingangle-shaped members 25!! and a back closure 25!. The angle-shapedmembers may be secured to the chassis by providing an extending portion252 thereon which is positioned between the insulating sheets H2 and H3of the chassis as illustrated in Fig. 6. Any suitable means may beprovided for securing insulating sheets H2 and H3 together with theportion 252 interposed therebetween. The angle-shaped members are alsosecured to the back closure member 25! which includes a hinged door 253providing access to the tubeside of the chassis. The angle members 250include notched out portions 254 around which antenna wire 255 it woundto provide a loop antenna. It is, therefore, seen that the chassisincludes all of the operating components of the receiver so that acompletely operable set is provided which can be completely adjusted andaligned prior to mounting thereof in a cabinet.

A modified method of securing the framework to the chassis isillustrated in Figs. 7 and 8 in which the chassis is shown as havingkeyshaped openings 266 in the comers thereof and the angle members 250include slots 23! in the end thereof adapted to be supported on thechassis. When the end of an angle member is compressed it can beinserted in the opening 256 after which it will expand to its normalshape and be thereby anchored to the chassis. The assembled structure isillustrated in Fig. 8.

Simple means for detachably securing the chassis in the radio cabinetare provided and are illustrated in Figs. 3, 9, 10 and 11. In Fig. 9 thecabinet is illustrated and the position of the chassis therein is shownin dot-dash lines. The cabinet includes posts 263 in the comer thereofon which pins 26! are mounted. The chassis includes openings at thecorners adapted to receive the pins and quick release type clips 262adapted to engage the pins 26! to hold the chassis in place. Theoperation of the quick release clips 262 is apparent from Figs. 3, 10and 11 wherein the clips are illustrated as comprising spring-likestrips 263 positioned between the sheets H2 and H3 of the chassisandhaving V-shaped engaging edges 264. A'latch 266 is provided havingportions resting between the insulating strip H3 and the spring portion263 so that as the latch is moved from the solid position to the dottedpositionshown in Fig. 5. the spring-like strip 263 is flexed from thesolid position to the dotted position thereby releasing the engagementof the V-shaped edges on the p t 26!.

In Fig. 12 an alternative detachable clip is illustrated which operatesgenerally similar to the clip illustrated in Figs. 3, 10 and 11. Thespring member 210, however, instead of being positioned between theinsulating sheets of the chassis, includes end portions 21! which extendthrough openings in the chassis and have struckout portions 212 whichsecure the clips to the chassis and hold the insulating sheets H2 and H3together. The use of such a clip would eliminate the need for separatemeans for holding the insulating sheets of the chassis together. A latch213 is provided for disengaging the clip from the pins 26!, the latchbeing arranged so that in the normal position'perpendicular to thechassis, the prongs 214 engage the pin 26!, and when it is moved againstthe chassis the pin 26! will be released.

In Fig. 37 there is illustrated a very small radio chassis in accordancewith the invention which does not include a loud speaker mounteddirectly on the chassis as in the receiver previously described. Thesize of an entire radio receiver chassis constructed in accordance withthis arrangement may bev only approximately 4 inches by 5% inches. Thischassis, as in the chassis previously described, has the tubes and otherlarge components supported on one side thereof and the terminals,resistors and condensers positioned on the other side. The chassis isformed by two insulating sheets 298 and 239 with conducting stripspositioned therebetween (Figs. 38 and 39). The strips and the terminalsthereon for mounting and connecting the components are of the sameconstruction as those previously described. The position of thecomponents, however, is particularly arranged so that a minimum amountof space is required and so that the conducting strips are as simple andhave as few crossovers as possible. In Fig. 37 the tubes are indicatedat 300, the intermediate frequency coil units at 33!, the electrolyticcondenser at 302, the output transformer at 303 and a dry rectifier isindicated at 304.

In Fig. 37 the pins of all of the units, that is the intermediatefrequency units and the electrolytic unit as well as the tubes areillustrated as being round. Connections are made to the pins byterminals as illustrated in Figs. 18 and 19. It is apparent that thepositioning of the conducting strips need not be as accurate forreceiving a round pin as'a flat terminal so that by using all roundpins, fewer types of terminals are required and it is not necessary thatthe strips and terminals be as accurately constructed. Both of thesefeatures are very material in reducing the cost of the chassis. It is tobe noted that resistors 305, 306, 301, 300, etc. are of various sizes,the size depending upon the value of the resistance required and uponthe amount of energy which is dissipated thereby. All of the condensersin the circuit with the exception of the electrolytic unit 302 are ofthe rolled paper type, reference numerals 309, M and 3H indicating someof the condensers which may be of varying sizes depending upon thecapacity thereof. The chassis of Fig. 3'7 includes conducting strips 335the manner illustrated in Fig. 32. By using two conducting strips joinedtogether, the assembly thereof on the insulating sheet 298 with theterminals thereof positioned in the openings of the sheet isfacilitated. The conducting strip 333 which is relatively long includesa loop 333 near the center thereof which is positioned in an opening inthe insulating sheet 298. This provides flexibility in the strip so thatthe terminals thereof will shift to receive the tube pins even whenthere is a slight error in the dimensions thereof due to manufacturingtolerances. It is to be noted that in Fig. 37, various resistors andcondensers are used to provide crossover of the various circuits. As anexample condenser 309 and resistor 30% both cross over the strip 335 andresistor 305 crosses over two different arms of conducting strip 335.These crossovers are in accordance with the detail views of Figs. 14, 25and 35.

Various ones of the conducting strips can be made identical to reducethe number of different parts and thereby further reduce the cost of thechassis. For example, conducting strips 3 50, SM. 342 and 343 are allidentical and conducting strips 3 and 345 are identical. By carefuldesign agreat number of identical strips can generally be used on anyparticular chassis to thereby simplify the construction of the chassis.

Fig. 38 shows a partial cross-sectional view of the chassis illustratingin particular the mounting of the rectifier 30d, the transformer 303,electrolytic condenser 302 and a paper condenser 382. It is noted thatthe rectifier 303 is secured to the chassis by a bolt 3i5 which ispositioned in an opening in the insulating sheet H2 so that it does notcontact components mounted on the tube side of the chassis. The bolt 3i5engages conducting strip 3I3 to form one terminal for the rectifier andthe other terminal of the rectifier is connected by the strip 3H5 withthe tube pin 3 I! as shown in the upper right hand corner of Fig. 3'7.The transformer 303 includes connecting pins 3! and 3l9 for connectingto conducting strips in the chassis in the manner previously describedwith reference to vacuum tubes.-

To facilitate the use of space, a paper condenser M2 is positioned onthe tube side of the chassis and ismounted perpendicular to the chassis.

and 336 which are joined at 333 in- 12 One connection to the condenser3l2 is made through conducting strip 320 which extends through anopening 32! in the insulating sheet 299 and the other connection is madeby" spring clip 322 which is secured to the transformer 303 in suchmanner to provide a ground connection forthe condenser.

Fig. 39 is a second cross-sectional view of the chassis of Fig. 37showing the mounting of the volume control 323 and the tuner 324. Inthis structure the volume control and tuner are mounted on the tube sideof the chassis with the control shafts therefor positioned perpendicularto the chassis and extending therethrough. The volume control includes aplurality of pins 325 for making connection thereto and for partiallysupporting the volume control on the chassis. A mounting lug 326 isprovided on the volume control which extends through an opening in thechassis and is twisted to thereby secure the volume control to thechassis. The tuner also contains three pins 321, 328 and 329 for makingelectrical connection with conducting strips, and supporting lugs 330and 3! for securely mounting the tuner on the chassis. Connection of thepins 327, 328 and 329 to the strips 3M, 360 and 34 5 respectively isshown in Fig. 37.

It is apparent from the foregoing that I have provided a simplifiedradio receiver construction wherein the various components of thereceiver are mounted on a chassis and interconnected without the usualwiring and soldered connections. As the insulating sheets can be veryrapidly stamped out and the conducting strips can also be very easilyand cheaply formed, the cost of the complete chassis including the mounting and connecting provisions is very low. In assembling the chassis, itis merely necessary to place the conducting strips on the insulatingsheet with the terminals and other projections on the strips extendingthrough the openings therein to position the same, and then secure thetwo insulating sheets together to form a chassis capable of completelyinterconnecting the components of the set. The placing of the componentson the chassis can then be very readily accomplished either by hand orby using mechanical means for feeding the components in place. After allthe operating components have been assembled on the chassis, the chassiscan then be mounted in a cabinet to provide a complete radio set.

In addition to the saving in cost in the construction of the chassis andassembly of the components thereon, a further reduction in cost isachieved by the simplification of the components. For example, theresistors used in the set can be very cheaply produced as they arepressed from resistance material and do not require terminals tendedscope of the invention as defined in the appended claims.

I claim:

1. Electronic equipment substantially free of bonded circuitconnections, comprising an elongated electrical component havingelectrical conl3 necting means at the ends thereof, a chassis includinga pair of insulating sheets with openings therein, and at least twopreformed conducting strips positioned between said sheets, each of'said strips having a U-shaped resilient terminal portion formed thereinand positioned in an opening in one of said sheets and extending to oneside of said chassis. said strips including portions on both sides ofsaid U-shaped resilient portions which are positioned between andsupported by said sheets, said terminal portions on said conductingstrips having conductive surfaces for engaging said conducting means onsaid elongated electrical component, said conductive surfaces beinpositioned to frictionally engage said conducting means to support saidelongated component therebetween on said one side of said chassis andmake electrical contact therewith.

2. Electronic equipment substantially free of bonded circuitconnections, comprising an elongated electrical component mounted onsaid chassis having electrical connecting means at the ends thereof, achassis including a pair of insulating sheets with openings therein andat least three preformed conducting strips positioned between saidsheets, two of said strips having U-shaped resilient terminal portionsformed therein and positioned in openings in one of said sheets andextending to one side of said chassis, said strips including portions onboth sides of said U-shaped resilient portions which are positionedbetween and supported by said sheets, said U-shaped terminal portionshaving conductive surfaces for engaging said conducting means on saidelongated electrical component, said conductive surfaces beingpositioned to frictionally engage said connecting means to support saidelongated component therebetween on said one side of said chassis andmake electrical contact therewith, said third conducting strip extendingbetween said sheets in the space between said terminal portions toprovide a circuit crossover.

3. Electronic equipment substantially free of bonded circuitconnections, comprising a chassis,

said chassis including a pair of insulating sheets with openingstherein, and at least two preformed conducting strips positioned betweensaid sheets, one of said strips having a U-shaped resilient terminalportion formed therein and positioned in an opening in one of saidsheets and extending to one side of said chassis, said one stripincluding portions on both sides of said U-shaped resilient portionwhich are positioned between and supported by said sheets, the other oneof said strips having one end thereof formed into a right angleprojection extending between the sides of said U-shaped terminalportion, said U-shaped resilient portion having conductive surfaces onthe inside of said sides thereof frictionally engaging said right angleprojection and making electrical contact therewith.

DONALD H. MITCHELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,697,215 Wolff Jan. 1, 19291,718,993 Wermine July'2, 1929 1,780,778 MacFadden Nov. 4, 19301,992,925 Lodge Feb. 26, 1935 2,017,940 Bessey Oct. 22, 1935 2,066,876Carpenter Jan. 5, 1937 2,174,107 Kenney Sept. 26, 1939 2,196,697 EbyApr. 9, 1940 2,244,009 Heinschatal June 3, 1941 2,256,803 Hauser Sept.23, 1941 2,268,619 Reid Jan. 6, 1942 2,270,166 Hiensch et a1 Jan. 13,1942 2,292,163 Shea. Aug. 4, 1942 2,411,528 Dodington Nov. 26, 1946FOREIGN PATENTS Number Country Date 269,729 Great Britain Apr. 28, 1927131,290 Australia Jan. 10, 1933

